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December 16, 2009

Isometric Circles

In the last post, I showed you how to turn on and cycle through the three isometric planes to help create 3D-looking drawings in 2D. But what if you need more than straight lines? What if you need circles?

The regular Circle command can't help you in an isometric drawing. What can is the Ellipse command, since circles projected in an isometric view appears as ellipses.

First, make sure your snap type is set to Isometric. Then, when you start the ellipse command, you'll see the following options:

Specify axis endpoint of ellipse or [Arc/Center/Isocircle]:

(If your snap style is set to Rectangular, you won't see Isocircle).

Once you enter I for Isocircle, you're prompted for the center point and a radius. You can either use snapping & tracking to specify these, or enter coordinates as usual. If you enter a number for the radius, you can just use the "real" radius of the circle -- you don't have to worry about doing any math to figure out the ellipse properties. The object you end up with is an ellipse whose axes are rotated to match the isometric angles.

The angle of the isocircle depends on your isoplane setting.

Need arcs instead? Just trim your isocircles.

(Don't ask me what the back side of this "cube" looks like now...I just trimmed some corners to make isometric arcs. But if one of you wants to draw the other side I'll post it...)